JP2023179644A - Ferrite magnetic core, coil component using them, and electronic component - Google Patents

Abstract

To provide a ferrite magnetic core, a coil component, and an electronic component, which can reduce a size and a weight while considering a heat radiation.SOLUTION: A ferrite magnetic core 1 includes: a column-like middle leg part 40; a first outer leg part 52 and a second outer leg part 53 that are arranged to a direction orthogonal to a shaft direction of the middle leg part so as to be separated to both sides of the middle leg part; and a first coupling part that couples the middle leg part and the first outer leg part, and a second coupling part that couples the middle leg part and the second outer leg part. The shaft direction of the middle leg part is a z-shaft direction, an opposite direction of both of the first and second outer leg parts, which are orthogonal to a z shaft is a y shaft direction, a direction which is orthogonal to a y shaft and the z shaft is a x shaft direction. When the ferrite magnetic core is viewed from an upper side of the z shaft direction after a base part of each leg part is set to a lower side, a width w1 of the x shaft direction of the first outer leg part is larger than a width w2 of the x shaft direction of the second outer leg part, and a width d1 of the first outer leg part along in a straight line of the y shaft direction passing through a center of the middle leg part is smaller than a width d2 of the second outer leg part along the straight line of the y shaft direction passing through the center of the middle leg part, and a constriction continued to the z shaft direction is provided on both side surfaces of the x shaft direction of the middle leg part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ferrite magnetic core used in various electronic devices, and coil components and electronic components using the same.

Electric vehicles, which are one type of electric transportation equipment such as EVs (Electric Vehicles) and PHEVs (Plug-in Hybrid Electric Vehicles), which have become rapidly popular in recent years, are equipped with devices such as high-output electric motors and chargers. The power supply devices used in these devices require coil components such as transformers and choke windings that can withstand high voltage and large current, and electronic components using the same. Coil components generate heat due to resistance loss in the windings and magnetic energy loss in the ferrite core. In particular, the heat generated by the windings is significant. Therefore, it is necessary to stabilize the temperature at a temperature slightly higher than the maximum temperature of the environment to which it is exposed, to prevent thermal runaway in which the ferrite core loses its magnetism, and to prevent thermal damage to the winding itself and the members that make up the coil components. It will be done.

A common method for dealing with heat generated by coil components is to release the heat to a heat sink that functions as a cooler, a frame with a large heat capacity, etc., via a mounted body such as a mounting board or a metal case. JP-A-2013-131540 and JP-A-2015-141918 disclose that the heat generated by the coil component 201 is radiated by bringing a heat radiating member (attached body 300) into contact with the ferrite magnetic core 102, as shown in FIG. ing. The heat dissipating member is made of a metal member with high thermal conductivity, such as a copper plate or an aluminum plate.

The so-called E-type ferrite core is known as a ferrite core used in coil parts (TDK Corporation, Ferrite core for Mn-Zn switching power supplies, [searched on February 15, 2018], Internet <URL : https://product.tdk.com/info/ja/catalog/datasheet/ferrite_mz_sw_e_ja.pdf>). As shown in FIG. 10, the E-type ferrite magnetic core includes a rectangular flat plate portion 160, a pair of outer leg portions 152 and 153 protruding from both ends of the flat plate portion 160, and an inner leg portion provided between them. It has leg portions 140. The E-type ferrite magnetic core 101 is generally symmetrical with outer legs 152 and 153 provided at rotationally symmetrical positions with respect to the center of the middle leg 140 that stands upright in the center of the flat plate part 160. .

As shown in FIG. 9, contact between the coil component 201 and the mounted body 300 on the back surface of the flat plate portion 160 of the ferrite magnetic core 102 is advantageous in that the contact area can be increased. However, since a thermal gap is formed in the heat path in the radial direction and width direction (y-axis direction) of the winding 120 due to the insulator that protects the conductor, heat conduction in the radial direction and width direction of the winding 120 is tends to be inferior to the circumferential direction of winding.

In addition, since the coil component 201 is configured by combining a pair of ferrite magnetic cores 102, 102, when viewed from the attached body 300, the thermal path (indicated by the arrow in the figure) between the ferrite magnetic cores 102, 102 has thermal conductivity due to the combination surface. A thermal gap 210 is formed that lowers the temperature. As a result, heat dissipation from the windings and ferrite cores on the side far from the attached body 300 in the y-axis direction tends to be insufficient, so additional measures may need to be taken to prevent thermal damage to the coil components. was there.

Furthermore, with the increasing density of circuit boards, there is a strong demand for electronic components to be smaller and lighter so that multiple electronic components can be placed closer together in a limited space, and from the perspective of reducing battery consumption. The area in which individual electronic components can be placed tends to be limited. When a ferrite magnetic core is downsized in order to make a coil component smaller and lighter, problems arise in that the amount of heat generated increases and the contact area with a heat dissipating member decreases, resulting in a decrease in heat dissipation performance.

Accordingly, an object of the present invention is to provide a ferrite magnetic core that allows coil components to be made smaller and lighter while taking heat radiation into consideration, as well as coil components and electronic components using the same.

That is, the ferrite magnetic core of the present invention includes a columnar middle leg portion,
a first outer leg portion and a second outer leg portion spaced apart from each other on both sides of the middle leg portion in a direction perpendicular to the axial direction of the middle leg portion;
a first connecting portion that connects the middle leg and the first outer leg at their bases;
A ferrite magnetic core having a second connecting portion connecting the middle leg portion and the second outer leg portion at their bases,
The axial direction of the middle leg is the z-axis direction, the direction in which the first and second outer legs face each other perpendicular to the z-axis is the y-axis direction, and the direction perpendicular to the y-axis and the z-axis is the x-axis. direction, and when the ferrite magnetic core is viewed from above in the z-axis direction with the base of each leg section facing downward,
A width w1 of the first outer leg in the x-axis direction is larger than a width w2 of the second outer leg in the x-axis direction,
The width d1 of the first outer leg along a straight line in the y-axis direction passing through the center of the middle leg is equal to the width d1 of the second outer leg along a straight line in the y-axis direction passing through the center of the middle leg. smaller than the width d2 along
The ferrite magnetic core is provided with a constriction continuous in the z-axis direction on both side surfaces of the middle leg in the x-axis direction.

Preferably, the middle leg is cylindrical.

In the ferrite magnetic core of the present invention, the first outer leg portion and the second outer leg portion have an outer surface on a side opposite to the side facing the middle leg portion,
The distance h1 from the central axis of the middle leg to the outer surface of the first outer leg and the distance h2 from the center axis of the middle leg to the outer surface of the second outer leg are h1<h2. It is preferable that the relationship is as follows.

The ferrite magnetic core of the present invention is preferably symmetrical with respect to the yz plane passing through the central axis of the middle leg.

In the ferrite magnetic core of the present invention, it is preferable that the first outer leg portion and the second outer leg portion have an arcuate inner surface on a side facing the middle leg portion.

In the ferrite magnetic core of the present invention, when measured along a straight line in the y-axis direction passing through the central axis of the middle leg, the distance from the center axis of the middle leg to the inner surface of the first outer leg and the Preferably, the distance from the central axis of the middle leg to the inner surface of the second outer leg is the same.

In the ferrite magnetic core of the present invention, it is preferable that the outer surface of the first outer leg portion is a flat surface.

In the ferrite magnetic core of the present invention, when viewed from above in the z-axis direction, the area S1 of the end face in the z-axis direction of the first outer leg portion and the area S2 of the end face in the z-axis direction of the second outer leg portion are approximately equal to each other. Preferably they are the same. The area S1 and the area S2 preferably satisfy the relationship S1×0.8≦S2≦S1×1.2.

A coil component of the present invention is a coil component including the ferrite magnetic core of the present invention and a winding arranged in the middle leg of the ferrite magnetic core.

The coil component of the present invention preferably has a bobbin including a body into which the middle legs of the pair of ferrite magnetic cores are inserted and around which a winding is wound.

In the coil component of the present invention, it is preferable that both ends of the winding are drawn out toward the second outer leg of the ferrite core.

The electronic component of the present invention is an electronic component using the coil component of the present invention,
The coil component is fixed to a metal mounting body having higher thermal conductivity than the ferrite magnetic core, with the outer surface of the first outer leg of the ferrite magnetic core in contact with or close to the mounting body. It is an electronic component. In the electronic component of the present invention, it is preferable that the electronic component is embedded in a resin containing a thermally conductive filler, and the surface of the resin is preferably exposed except for the surface that is in contact with the object to be mounted.

According to the present invention, it is possible to provide a ferrite magnetic core that makes it possible to reduce the size and weight of coil components while taking heat radiation into consideration, as well as coil components and electronic components using the same.

1 is a front view showing the structure of a ferrite magnetic core according to an embodiment of the present invention. FIG. 2 is a front view showing the structure of a ferrite magnetic core with the dimension description removed from FIG. 1. FIG. 3 is a right side view of the ferrite magnetic core shown in FIG. 2. FIG. 3 is a rear view of the ferrite magnetic core shown in FIG. 2. FIG. 3 is a plan view of the ferrite magnetic core shown in FIG. 2. FIG. 3 is a bottom view of the ferrite magnetic core shown in FIG. 2. FIG. 3 is a perspective view of the ferrite magnetic core shown in FIG. 2. FIG. FIG. 1 is a perspective view showing a state in which a coil component of the present invention, which is configured by combining ferrite magnetic cores according to an embodiment of the present invention, is arranged on a surface of an attached body. It is a perspective view of the conventional coil component arrange|positioned on the surface of a to-be-installed object. It is a front view showing an example of a conventional ferrite magnetic core.

Hereinafter, a ferrite magnetic core according to an embodiment of the present invention, and a coil component and an electronic component using the same will be specifically explained, but the present invention is not limited thereto and does not depart from the gist of the present invention. It is of course possible to make various changes within the scope. In addition, the drawings used in the explanation mainly depict the main parts and omit details as appropriate so that the gist of the invention can be easily understood. Regarding the ferrite magnetic core, coil components, and electronic components of the present invention, parts having the same function are given common numbers and symbols throughout the drawings.

[1] Ferrite magnetic core FIGS. 1 to 8 show the structure of a ferrite magnetic core 1 according to an embodiment of the present invention. The ferrite magnetic core 1 of the present invention includes a columnar middle leg 40, and first outer legs spaced apart from each other on both sides of the middle leg 40 in a direction perpendicular to the axial direction of the middle leg 40. 52 and a second outer leg 53, a first connecting portion 61 that connects the middle leg 40 and the first outer leg 52 at their bases, and the middle leg 40 and the second outer leg. 53 at their bases.

That is, in the ferrite magnetic core 1, the first outer leg portion 52, the middle leg portion 40, and the second outer leg portion 53 arranged in a line connect the first connecting portion 61 and the second connecting portion 62 at their bases. and are configured to protrude in the same direction. Note that the first outer leg portion 52 and the second outer leg portion 53 are also referred to as a pair of outer leg portions.

The axial direction of the middle leg portion 40 (the direction in which each leg protrudes) is the z-axis direction, and the direction in which the first outer leg portion 52 and the second outer leg portion 53, which are orthogonal to the z-axis, face each other is the y-axis direction. The x-axis direction is the direction orthogonal to the z-axis, and the ferrite magnetic core 1 is aligned in the z-axis direction with the base of each leg (middle leg 40, first outer leg 52, and second outer leg 53) facing downward. When viewed from above, the first outer leg section 52 and the second outer leg section 53 have different widths in the x-axis direction, and a straight line in the y-axis direction passing through the center O of the middle leg section 40 (hereinafter referred to as "the middle leg"). The width w1 of the first outer leg portion 52 in the x-axis direction has an asymmetrical shape with different widths along a straight line in the y-axis direction passing through the central axis of the first outer leg portion 52 (also referred to simply as a “straight line in the y-axis direction”). is larger than the width w2 of the second outer leg portion 53 in the x-axis direction, and the width d1 of the first outer leg portion 52 along the straight line in the y-axis direction is larger than the width w2 of the second outer leg portion 53 along the straight line in the y-axis direction. The width is smaller than the width d2. In the present invention, the middle leg portion 40 has a circular shape when viewed in the z-axis direction (the shape when the ferrite magnetic core 1 is viewed from above in the z-axis direction with the base of each leg portion facing downward), that is, the middle leg portion Preferably, portion 40 is cylindrical.

In this application, the center O of the middle leg 40 is defined as the center of a circle circumscribing the shape of the middle leg when viewed in the z-axis direction. For example, if the middle leg has a circular shape when viewed in the z-axis direction (that is, the middle leg is cylindrical), the center of the circle is the center O. Further, for example, if the shape of the middle leg as viewed in the z-axis direction is a square (that is, the middle leg has a regular square prism shape), the center O is the intersection of two diagonals of the square. Further, the central axis of the middle leg is defined as the axis in the z-axis direction passing through the center O of the middle leg.

The inner surface 52d1 of the first outer leg 52 on the side facing the middle leg 40 is aligned with the outer shape of the winding 120, which is arranged on the middle leg 40 and is made by winding a conductive wire to a predetermined number of turns and diameter. , the inner surface 53d of the second outer leg portion 53 on the side facing the middle leg portion 40 is an arcuate curved surface. In addition, the distance from the central axis (center O) of the middle leg 40 to the inner surface 52d1 of the first outer leg 52 and the central axis (center The distance from O) to the inner surface 53d of the second outer leg portion 53 is the same.

The first outer leg portion 52 and the second outer leg portion 53 have an outer surface 52c and an outer surface 53c, respectively, on the side opposite to the middle leg portion 40 (the inner surfaces 52d1 and 53d), and The distance h1 from the center axis (center O) of the section 40 to the outer surface 52c of the first outer leg section 52, and the distance h1 from the center axis (center O) of the middle leg section 40 to the outer surface 53c of the second outer leg section 53. The distance h2 has a relationship of h1<h2. That is, the middle leg portion 40 has a center O (central axis) with respect to the midpoint of a line segment connecting one end (outer surface 52c) and the other end (outer surface 53c) of the ferrite magnetic core 1 in the y-axis direction. It is arranged at a position biased toward the first outer leg portion 52 side. The middle leg portion 40 only needs to have a cross-sectional area that does not cause magnetic saturation during use, and in the illustrated example, the shape when viewed from above in the z-axis direction is circular, but it may have another shape. Good too.

In the illustrated example, when viewed from above in the z-axis direction, the area S1 of the end face in the z-axis direction of the first outer leg part 52 and the area S2 of the end face in the z-axis direction of the second outer leg part 53 are almost the same, In addition, the area S3 of the end face in the z-axis direction of the middle leg portion 40 is approximately the same as the sum of the area S1 and the area S2. Since the middle leg part 40 is a part where the winding wire 120 is arranged and is likely to cause magnetic saturation, the area S3 may be set larger than the sum of the area S1 and the area S2, and the first outer leg part 52, Since leakage magnetic flux is likely to occur in the second outer leg portion 53, the area S3 of the middle leg portion 40 may be made smaller than the sum of the area S1 and the area S2. In that case, the area S3 of the middle leg portion 40 needs to be set so as not to cause magnetic saturation. Further, the area S1 and the area S2 may be made different as long as the setting does not cause magnetic saturation, but in consideration of miniaturization of the ferrite magnetic core 1, it is desirable that they be the same.

Here, "area S1 and area S2 are almost the same" means that area S1 and area S2 are substantially the same, and similarly, "area S3 is almost the same as the sum of area S1 and area S2". indicates that area S3 is substantially the same as the sum of area S1 and area S2. Specifically, the area S1 and the area S2 preferably satisfy the relationship S1×0.8≦S2≦S1×1.2, and more preferably satisfy the relationship S1×0.9≦S2≦S1×1.1. Area S3 and area S1 + area S2 preferably satisfy the following relationship: (S1+S2)×0.8≦S3≦(S1+S2)×1.2, and (S1+S2)×0.9≦S3≦(S1+S2) It is more preferable to satisfy the relationship ×1.1.

The side surface of the ferrite magnetic core 1 in the x-axis direction includes constrictions 71 and 72 that are continuous with the side surface 40a of the middle leg portion 40. The ferrite magnetic core 1 is usually formed by compressing ferrite granules and sintering the compact, but by providing constrictions 71 and 72, the density difference within the compact that occurs during molding can be reduced. It is possible to reduce the occurrence of deformation, cracks, etc. in the middle leg portion 40 during sintering. Further, the constrictions 71 and 72 can also be used for positioning the bobbin to be combined with the ferrite magnetic core 1.

A side surface 62a of the second connecting portion 62 extending from the constrictions 71, 72 toward the second outer leg portion 53 is parallel to the y-axis direction and is linear, and a side surface 53a of the second outer leg portion 53 in the x-axis direction, Continuing with 53b. Further, the side surface 61a of the first connecting portion 61 facing the first outer leg portion 52 is inclined at a predetermined angle with respect to the y-axis direction so that the first outer leg portion 52 side is wide.

At a portion where the first connecting portion 61 becomes wide and connects to the first outer leg portion 52, the width of the first outer leg portion 52 in the x-axis direction is larger than the width of the first connecting portion 61 in the x-axis direction, That is, they form surfaces 52d2 and 52d3 that protrude with a step in the x-axis direction and connect the arc-shaped inner surface 52d1 of the first outer leg portion 52 and the side surfaces 52a and 52b in the x-axis direction.

Each side surface of the first and second outer leg sections 52, 53, the side surface of the middle leg section 40, and each side surface of the first and second connecting sections 61, 62 are all connected to the z-axis of each leg section or each connecting section. It is continuous from the upper end surface side to the back surface 80 in the direction.

In the illustrated example, the ferrite magnetic core 1 is symmetrical with respect to the y-z plane passing through the center axis of the middle leg 40, that is, with respect to the straight line in the y-axis direction passing through the center O of the middle leg 40 in FIG. Although the shapes are symmetrical, there may be some differences.

The outer surface 52c of the first outer leg portion 52, the outer surface 53c of the second outer leg portion 53, and the back surface 80 (the first and second outer leg portions 52, 53, the middle leg portion 40, and the first and second connection The back surfaces of portions 61 and 62 are both flat surfaces. In order to prevent the molded product from separating from the mold during molding and to prevent chipping and damage at the ridge corners, the edges of the back 80 are chamfered in a single pattern, and the ridge corners of each part have curved surfaces. There is a certain amount.

[2] Coil component The ferrite magnetic core 1 of the present invention and the winding 120 disposed on the middle leg portion 40 constitute a coil component. FIG. 8 is a perspective view showing the appearance of the coil component 200. Preferably, the coil component 200 further includes a bobbin (not shown). The bobbin has a body into which a middle leg 40 is inserted and a winding 120 is wound thereon, and the middle legs 40 of a pair of ferrite magnetic cores 1 are inserted into the body and combined to form a coil component 200. Configure. It is preferable that the coil component 200 is fixed by pasting a tape (not shown) on the outer periphery of the combined ferrite magnetic cores 1, 1 or by adhesive.

The bobbin is preferably formed of a resin having excellent insulation properties, heat resistance, and moldability, preferably polyphenylene sulfide, liquid crystal polymer, polyethylene terephthalate, polybutylene terephthalate, etc., and is formed by a known method such as injection molding. Can be used in molded form

The conductive wire used for the winding 120 is a coated wire in which a conductor made of a conductive material such as copper, aluminum, or an alloy thereof is provided with an insulating coating. Generally, an enameled wire coated with polyamide-imide insulating material is used as the conducting wire, and it is preferable to use a litz wire made by twisting a plurality of enameled wires. The number of turns of the winding 120 can be appropriately set based on the required inductance, and the wire diameter can also be appropriately selected depending on the current to be applied.

The coil component 200 is used with the outer surface 52c of the first outer leg portion 52 of the ferrite magnetic cores 1,1 in contact with or in close proximity to the metal attachment body 300. The object to be mounted 300 may be made of a non-magnetic metal with excellent thermal conductivity, such as aluminum or its alloy, magnesium or its alloy, copper or its alloy, or the like. In order to improve the adhesion between the attached body 300 and the ferrite magnetic core 1, a highly heat-resistant heat dissipating grease may be applied.

As shown in FIGS. 1 and 8, the height (dimension in the y-axis direction) of the coil component 200 is determined by the size of the ferrite magnetic core 1, and the width (dimension in the x-axis direction) of the coil component 200 is determined by the size of the coil component 200 (dimension in the x-axis direction). Defined by the winding diameter. In the ferrite magnetic core 1 of the present invention, the width w1 of the first outer leg portion 52 in the x-axis direction is made larger than the width w2 of the second outer leg portion 53 in the x-axis direction without exceeding the outer shape of the winding 120, The area facing the attached body 300 is increased. Preferably 1.2×w2≦w1, more preferably 1.4×w2≦w1.

Then, the width d1 of the first outer leg portion 52 along the straight line in the y-axis direction is made smaller than the width d2 of the second outer leg portion 53 along the straight line in the y-axis direction, and the width of the first outer leg portion 52 is By making d1 thinner, the distance between the winding 120 and the attached body 300 is reduced and the heat path is shortened. Preferably 0.3×d2≦d1≦0.7×d2, more preferably 0.4×d2≦d1≦0.6×d2. Furthermore, by setting the distance h1 from the central axis of the middle leg portion 40 to the outer surface 52c of the first outer leg portion 52 and the distance h2 from the outer surface 53c of the second outer leg portion 53 to the relationship h1<h2. , the middle leg portion 40 is arranged so as to be biased toward the first outer leg portion 52 side. Furthermore, by making the area S1 of the end face in the z-axis direction of the first outer leg part 52 and the area S2 of the end face in the z-axis direction of the second outer leg part 53 almost the same, By reducing the width H in the direction, the height of the coil component 200 is reduced.

Furthermore, the position of the combined surface of the ferrite magnetic cores 1, 1 is set to avoid a position where a thermal gap 210 is formed in the middle of the heat path as in the conventional case.

According to such a configuration, the heat generated in the winding 120 can be efficiently released to the attached body 300 through the ferrite magnetic core 1, and the winding 120 in a portion far from the attached body 300 (a portion far away in the y-axis direction) Also, the heat generated by the ferrite magnetic core 1 can be quickly released to the outside because heat dissipation is ensured by a heat path that does not involve a thermal gap and a heat path in the circumferential direction of the winding 120 itself.

In addition, by pulling both ends (not shown) of the winding 120 toward the second outer leg 53 of the ferrite magnetic cores 1,1 (in the direction of arrow A in FIG. 8), the width dimension of the coil component 200 is increased. Since the height defined by the ferrite magnetic cores 1,1 can be reduced without increasing the height, the coil component 200 can be made smaller.

[3] Electronic component The coil component 200 is fixed to a metal mounting body 300 and embedded in a resin containing a heat conductive filler to form an electronic component. The resin is preferably a silicone resin, and the heat conductive filler is preferably selected from ceramics with excellent heat conductivity such as Al ₂ O ₃ , ZrO ₂ , SiO ₂ , Si ₃ N ₄ and MgO. It is desirable to adjust the amount of ceramic filler mixed with the silicone resin so as to obtain desired heat dissipation properties, deformability, and strength. The heat dissipation performance of the coil component 200 can be further enhanced by the resin containing the heat conductive filler.

Claims (15)

A columnar middle leg,
a first outer leg portion and a second outer leg portion spaced apart from each other on both sides of the middle leg portion in a direction perpendicular to the axial direction of the middle leg portion;
a first connecting portion that connects the middle leg and the first outer leg at their bases;
A ferrite magnetic core having a second connecting portion connecting the middle leg portion and the second outer leg portion at their bases,
The axial direction of the middle leg is the z-axis direction, the direction in which the first and second outer legs face each other perpendicular to the z-axis is the y-axis direction, and the direction perpendicular to the y-axis and the z-axis is the x-axis. direction, and when the ferrite magnetic core is viewed from above in the z-axis direction with the base of each leg section facing downward,
A width w1 of the first outer leg in the x-axis direction is larger than a width w2 of the second outer leg in the x-axis direction,
The width d1 of the first outer leg along a straight line in the y-axis direction passing through the center of the middle leg is equal to the width d1 of the second outer leg along a straight line in the y-axis direction passing through the center of the middle leg. smaller than the width d2 along
A ferrite magnetic core including a constriction continuous in the z-axis direction on both sides of the middle leg in the x-axis direction. The ferrite magnetic core according to claim 1,
A ferrite magnetic core in which the middle leg has a cylindrical shape. In the ferrite magnetic core according to claim 1 or 2,
The first outer leg portion and the second outer leg portion have an outer surface on a side opposite to the side facing the middle leg portion,
The distance h1 from the central axis of the middle leg to the outer surface of the first outer leg, and the distance h2 from the center axis of the middle leg to the outer surface of the second outer leg, are such that h1<h2 A ferrite magnetic core with the following relationship. The ferrite magnetic core according to any one of claims 1 to 3,
A ferrite magnetic core that is symmetrical with respect to the yz plane passing through the central axis of the middle leg. The ferrite magnetic core according to any one of claims 1 to 4,
The first outer leg portion and the second outer leg portion are ferrite magnetic cores having an arcuate inner surface on a side facing the middle leg portion. The ferrite magnetic core according to claim 5,
When measured along a straight line in the y-axis direction passing through the central axis of the middle leg, the distance from the center axis of the middle leg to the inner surface of the first outer leg and from the center axis of the middle leg The ferrite magnetic core has the same distance to the inner surface of the second outer leg. The ferrite magnetic core according to any one of claims 1 to 6,
A ferrite magnetic core, wherein an outer surface of the first outer leg portion is a flat surface. The ferrite magnetic core according to any one of claims 1 to 7,
A ferrite magnetic core in which an area S1 of an end face in the z-axis direction of the first outer leg portion and an area S2 of an end face in the z-axis direction of the second outer leg portion are approximately the same when viewed from above in the z-axis direction. The ferrite magnetic core according to claim 8,
The area S1 and the area S2 are
S1×0.8≦S2≦S1×1.2
A ferrite magnetic core that satisfies the relationship. A coil component comprising the ferrite magnetic core according to any one of claims 1 to 9 and a winding arranged in the middle leg of the ferrite magnetic core. The coil component according to claim 10,
A coil component having a bobbin including a body portion into which the middle leg portions of the pair of ferrite magnetic cores are inserted and around which a winding wire is wound. The coil component according to claim 11,
A coil component in which both ends of the winding are drawn out toward the second outer leg side of the ferrite magnetic core. An electronic component using the coil component according to any one of claims 10 to 12,
The coil component is fixed to a metal mounting body having higher thermal conductivity than the ferrite magnetic core, with the outer surface of the first outer leg of the ferrite magnetic core in contact with or close to the mounting body. electronic components. The electronic component according to claim 13,
Electronic components embedded in resin containing heat-conducting filler. The electronic component according to claim 14,
The surface of the resin is exposed except for the surface that is in contact with the object to be mounted.

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